Rear brake = no bueno

Started by take risks, July 03, 2012, 05:22:06 PM

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take risks

Backstory.
'07 695.
Brakes worked fine and engaged well. I had good pressure.

My rear started squeaking. So I investigated. I tried to remove the pads like I successfully did before:
Remove the split pin (1) from the caliper retaining pin. The split pin is on caliper inner side. Force the brake pads
apart to force the caliper pistons into their housings. Withdraw the brake pad retaining pin (2) from the outside.


However I could not get the brake retaining pin out. (It is the pin that the rear pads slide along on the on the top)
So I figured I needed to take the caliper apart. When I did that, 1/2 teaspoon of fluid came out. Made a note of that o-ring in the front part of the caliper where the fluid passes through. Could not get the brake retaining pin out still. Put everything back together including the little o-ring.

Rear brakes barely engage with the lever all the way down.
The fluid level is near the max.
When I put a Mity-Vac on the bleeder valve with the bleeder valve fully closed I can still pull air through the bleed valve.

Please help. Thanks.
2000 VFR 800 - wrecked
2007 Ducati Monster 695

DarkStaR

#1
<Captain Obvious>
I'm sure you know this, but taking the calipers apart was a mistake.
</Captain Obvious>

The Mity-Vac is pulling air through the threads of the bleeder. Not uncommon.

Bleed it the old fashion (pump the lever>hold the lever down>open the bleeder>release the air>close the bleeder>repeat).

I have zero luck using a Mity-Vac to get the last bit of air out of the brake/clutch system. YMMV Some can do it just fine apparently.

Howie

Maybe through the bleeder, maybe through the caliper halves.

take risks

@DarkStaR
It had to be done. The pin was frozen in there.
I'll go old school on it today.

@Howie
I don't know. I cranked them down pretty good.

Anyone take the caliper apart before and run across something that I did not describe?
Trying to find a diagram of the caliper to make sure I did not lose a tiny piece.

Thanks again.
2000 VFR 800 - wrecked
2007 Ducati Monster 695

koko64

I have more luck bleeding from the banjo bolt on my upside down caliper. There's always a big bubble of air there. You need well placed rags to protect paint if you dont have a bleed nipple on the banjo.
2015 Scrambler 800

Howie

Forgot your caliper is mounted up side down.  Remove the caliper.  Place a piece of hard material between the pads that is about the width of the rotor.  Hold the caliper so the bleeder screw faces up.  Now bleed.

corey

<3 rear brake design...

(sarcasm)
When all the land lays in ruin... And burnination has forsaken the countryside... Only one guy will remain... My money's on...

koko64

Quote from: howie on July 04, 2012, 09:02:27 PM
Forgot your caliper is mounted up side down.  Remove the caliper.  Place a piece of hard material between the pads that is about the width of the rotor.  Hold the caliper so the bleeder screw faces up.  Now bleed.

That also. Sometimes I'd place it on the top part of the disc.

I should have said banjo bolt on the master cylinder. I have found that to be a high point for bubbles. I might buy a bleeder type banjo for it one day, but so far I have been lucky not to lose paint using protective rags.
2015 Scrambler 800

take risks

Thanks for your help.

The issue was resolved going old school with the turn bleeder screw, engage brake, close screw, and release brake, repeat, repeat, repeat.
And that surprised me. I did not do it the way DarkStaR mentioned, but got the same result; good brake sensitivity. I guess his was would work better at getting the air out. I needed both the air and old fluid out. Regardless it is all good now.

Seperating the caliper halves worked fine. It allowed me to get all that fluid out by depressing the cylinders. (Be prepared for the fluid to fly out!) It kinda all comes at once.

The bleed nipple does point skyward so you dont have to remove the caliper for just a bleed.
2000 VFR 800 - wrecked
2007 Ducati Monster 695

showerfan

i had a problem with my rear brake, then i realized how useless it is [laugh] now i use the engine [clap]
Give me a shout if you know any good motorcycle detailers in the Westchester area.

Curmudgeon

Quote from: showerfan on July 09, 2012, 08:17:58 PM
i had a problem with my rear brake, then i realized how useless it is [laugh] now i use the engine [clap]
;D

What are brakes?  ;)
2011 796 ABS "Pantah" - Rizoma Bar, 14T, Tech Spec, Ohlins DU-737, Evaps removed, Sargent Seat, Pantah skins

Nottsbiker

Quote from: corey on July 04, 2012, 09:17:14 PM
<3 rear brake design...

(sarcasm)

All Italian bikes with this rear calliper design suffer with this issue along with my Tuono which requires  every couple of months. Tbh I often leave it
Ducati Monster 900 (project) Aprilia Tuono 1000

BastrdHK

Get yourself a torque wrench and make sure you have the proper spec on the caliper bolts.  Glad you sorted your issue, but why did you not just drive the pin out with a punch? I don't understand disassembling the caliper?

M-ROCin' it!!!

take risks

@BastrdHK
I banged it good, but it did not pop out. Once I had the caliper apart, it still took a couple of good smacks.
Had an 'off-track' moment last trackday and ended up with all kinds of goodies on/in my bike. (Rocks, bushes, giant bug guts)

The pin is straight, it was just super stuck. Torqued to spec. Thanks all.
2000 VFR 800 - wrecked
2007 Ducati Monster 695